Problem: Simplify the following expression: $k = \dfrac{10y}{2z - 12} + \dfrac{2z}{2z - 12}$ You can assume $x,y,z \neq 0$.
Answer: Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{10y + 2z}{2z - 12}$ The numerator and denominator have a common factor of $2$, so we can simplify $k = \dfrac{5y + z}{z - 6}$